1. Field of the Invention
This invention relates to a method for charging a liquid into a container through a liquid charging opening, which is formed at an upper end of the container.
2. Description of the Prior Art
In general, a container for containing a liquid therein is provided with a liquid charging opening, which is formed at an upper end of the container and through which the liquid is to be charged into the container. Those containers are roughly classified in accordance with the form or structure into (a) the containers, such as bottle-like containers constituted of synthetic resins, glass, metals, or the like, which are capable of supporting themselves and show little change in shape before they are charged with a liquid and after they are charged with the liquid, and (b) the containers, such as bag-like containers constituted of synthetic resin films, rubber, or the like, which are not capable of supporting themselves and show a large change in shape before they are charged with a liquid and after they are charged with the liquid.
In general, when a liquid is to be charged into a bottle-like container, the container, which is being supported by itself, is fed into a liquid charging means, and the liquid is charged by the liquid charging means into the container, which is being supported by itself. Also, in general, when a liquid is to be charged into a bag-like container, the container is fed into a liquid charging means while the upper end of the container is being held and the container is being thereby suspended. Thereafter, the liquid is charged by the liquid charging means into the container, which is being suspended.
With the operation for charging a liquid into the bottle-like container, the container can be fed into the liquid charging means, while the container is being supported by itself. Therefore, the working efficiency can be kept high. However, empty bag-like containers, which have not yet been charged with the liquid, occupy a large space as compared with the containers which have been charged with the liquid. Therefore, the efficiency, with which the empty containers are conveyed, and the efficiency, with which the empty containers are stored, cannot be kept high. Also, the equipment for conveying the empty containers into the liquid charging means must have a size corresponding to the large space, which is occupied by the empty containers, and therefore the equipment for conveying the empty containers cannot be kept small in size.
With the operation for charging a liquid into the bag-like container, the space occupied by empty containers can be kept small. However, when the container is fed into the liquid charging means, the container cannot be supported by itself. Therefore, a means and an operation for holding the upper end of the empty container and suspending the empty container are required when the empty container is fed into the liquid charging means. Also, the posture of the empty container will vary when the empty container is fed into the liquid charging means, and therefore a comparatively large conveyance space must be set by taking the variation in the posture of the empty container into consideration.
Further, in cases where a liquid is charged into a bottle-like container or a bag-like container, basically, a liquid charging amount, which is other than the specified amount corresponding to the size of the container, cannot be set for a single size of the container. Specifically, in cases where a liquid is charged into a bottle-like container, charging of the liquid in an amount smaller than the specified amount is not carried out generally, though possible, because the liquid charging volumetric efficiency becomes low. In cases where a liquid is charged into a bag-like container, if the liquid charging amount is smaller than the specified amount, the shape of the container after being charged with the liquid will not be stable. Therefore, such charging of the liquid in an amount smaller than the specified amount is not carried out in practice.